2nd Generation of systems for mobile communications (2G) is characterized by its adoption of digital technology. Compared to 1G systems, 2G systems offer improved voice quality and enhanced capacity. Historically, 2G systems supported voice communication and had a limited data capacity ranging from 9.6 to 14.4 Kbps.
2G systems are standardized regionally, allowing for regional roaming but not global roaming. Mobile terminals in 2G systems are smaller, boast longer standby times, and are more cost-effective. This widespread availability of 2G systems has transformed mobile communications into a widely accessible commodity.
Key 2G standards include:
- GSM (Global System for Mobile Communications)
- D-AMPS (Digital AMPS)/IS-136
- PDC (Personal Digital Cellular)
- cdmaOne/IS-95
2G systems initially operated on a circuit-switched (CS) model, but later enhancements enabled higher-speed packet-switched (PS) data transmission. These advanced features, such as GPRS for GSM, are often referred to as 2.5G.